Cut-off motion fob puppet-valves



'IMIN fl TED STATES sAML. H. GILMAN, OF CINCINNATI, OHIO.

CUT-OFF MOTION FOR PUPPET-VALVES.

Specication of Letters Patent No. 7,830, dated December 10, 1850.

To all whom t may concern.'

Be it known that I, SAMUEL H. GILMAN, of Cincinnati, Hamilton county,Ohio, have invented new and useful Improvements in Valve-Gearing ofSteam-Engines; and I do hereby declare the following to be a full,clear, and exact description of the nature, construction, and operationof the same, reference being had to the annexed drawings, making part ofthis specification.

Figure l in the said drawings is a View of the working'parts within thesteam chamber or chest, the valves with their guide, seats and movablechambers being drawn in section, more clearly to show theirconstruction. Fig. 2 is a vertical section through the axis of the rockshaft. Fig. 3 is an enlarged view of cut olf movement in its trippedposition.

The same or similar parts are indicated by like letters in the severalfigures.

The nature of my invention consists in a provision for cutting olf atany desired point the supply of steam to the cylinder when drop valvesare used, by making the lifters vibratable upon the rock shaft andcausing them to act in obedience to the motions of gravitating toggleswhich being tripped by impact with an adjustable stop, allow the lifterto rotate upon the shaft and the valve to descend.

This invention is shown as applied to the supply valves of anoscillating engine, the steam chest of which is upon the trunnion side,the trunnion making part of the supply passage and being cast in onepiece with the front of the steam chest.

The arrangement of the chest as seen in the drawing has a twofoldobject, namely to givethe rock shaft which lifts the supply valves asnearly equal action in both halves of its sweep as is consistent withthe attachment of the trunnion and a due approximation to equipoise ofthe cylinder upon the axis of its vibration.

The parts represented in the drawing and not lettered, need noparticular description, as they merely constitute what is usual inoscillating engines. I shall therefore only refer to by letter anddescribe the parts involved in the invention.

(a) is an arm, attached to and vibrating with the rock shaft (b).

(c) is the lifter of the upper valve and (c) is the lifter of the lowervalve; both l(ibf;ers have free play upon the rock shaft` (d) is thefoot of valve stem (e).

All t-he valve stems are hollow for the reception of guide rods (f)which are attached at one end of the cap of the valve chest, andsupersedes entirely the necessity of any bridges or other obstructionsathwart the valve opening.

The free extremity of each lifter is jointed to the link (g org) of atoggle which is completed by the said link being jointed to another linkor L) which is in its turn jointed to an arm or z") projecting down fromand vibrating with the rock shaft, the second link (71,) of the toggleextending down beyond the joint sutliciently far, for the purpose, whenallowed to gravitate, of counterbalancing and fixing the lifter foroperating the valve, and also for the purpose of letting the valves dropgently down to its seat, when by the motion of the rock shaft, theprojection by impact with the pin (Z) is tripped upward. The uppermember of the link (it) is by the superior gravity of the loaded end(le) caused to press against the rock shaft (b) and thus affords throughthe link (g) a fixed pointof support for the lifter (c) so that it maybe able to lift the valve, but when the projection (la) is lifted bycontact with the adjustable stop-the knuckle of the toggle is instantlybent in the opposite direct-ion, and the lifter consequently depressedso as gently to drop and ease down the supply valve upon its seat.

The adjustable stop is operated as seen by a rack (m) and pinion (n)within the steam chest, an index arm (o) being fixed upon the shaft ofthe pinion without side the steam chest I-Iaving thus fully, clearly,and exactly described the nat-ure and construction Of my invention, whatI claim therein as new and desire to secure by Letters Patent is-Raising and dropping at any desired point the puppet valves that admitsteam to the cylinders by means of a lifter that vibrates, with and uponthe usual rock shaft, the said lifter being operated by a gravitatingand counterbalancing toggle as described so that the lifter n the mannerdescribed or `its In testimony whereof, I have hereunto set equivalentis xed for raising the Valve and my hand before two subscribingwitnesses. is depressed and allowed gradually and SAMUEL H GILMAN easilyto drop the valve when the C'Ounter- 5 balance of the toggle is operatedby the adlVtnesses:

justable stop, substantially as herein den EDWARD H. KNIGHT, scribed.THos. G. CLINTON.

